Aqueous liquid enzymatic detergents are well-known in the prior art. The enzymes incorporated in liquid detergents have mostly been Bacillus protease, but the prior art also suggests that incorporation of enzymes other than Bacillus proteases may be useful, e.g., other enzyme types (such as amylases, lipases and cellulase) as well as enzymes of non-Bacillus origin (e.g., fungal enzymes). A major problem which is encountered with such compositions is that of ensuring a sufficient storage stability of the enzymes in such compositions.
The prior art deals extensively with stabilization of enzymes in liquid detergents. It is known that a number of commonly used detergent ingredients may reduce their storage stability, e.g., aniomic surfactants and detergent builders. The prior art also suggest that various materials that are not detergent-active can be incorporated as enzyme stabilizers.
It can also be mentioned that JP-A 58-194,806 and JP-A 58-069,808 suggest the incorporation of imidazoline amphoteric surfactant in tooth paste to improve the storage stability of amylase; this teaching has apparently not been utilized in detergents.
It is now the object of the invention to provide a liquid detergent composition comprising a detergent enzyme with improved storage stability.